The LP3985 is designed for portable and wireless applications with demanding performance
and space requirements. LP3985 performance is optimized for battery-powered systems to deliver
ultra low noise, extremely low dropout voltage, and low quiescent current. Regulator ground current
increases only slightly in dropout, further prolonging the battery life.
The LP3985 is stable with a small 1-µF ±30% ceramic or high-quality tantalum output
capacitor. The DSBGA requires the smallest possible PC board area – the total application circuit
area can be less than 2 mm × 2.5 mm, a fraction of a 1206 case size.
An optional external bypass capacitor reduces the output noise without slowing down the
load transient response. Fast startup time is achieved by utilizing an internal power-on circuit
that actively pre-charges the bypass capacitor.
Power supply rejection is better than 50 dB at low frequencies and starts to roll off at
1 kHz. High power supply rejection is maintained down to low input voltage levels common to battery
operated circuits.
The device is ideal for mobile phone and similar battery-powered wireless applications.
It provides up to 150 mA, from a 2.5-V to 6-V input. The LP3985 consumes less than 1.5 µA in
disable mode and has fast turn-on time less than 200 µs.
The LP3985 is available with fixed output voltages from 2.5 V to 5 V. Contact Texas
Instruments Sales for specific voltage option needs.
